WRDJ205

I realize that’s several things different. To make sure it wasn’t an anomaly I took it all apart and reassembled and it worked again. There is an appreciable delay in the transmit (a couple of seconds) but if you wait it out it does work. Another change was in the transmission time. With the connector box cable there must be something that recognizes transmission. If you aren’t talking it stops transmission. Almost like a VOX on the radio would work. I think that was also throwing me off before. So for now, I have all the working components with the main parts being the duplexer (tuned for multiple pairs) and the two H3 radios connected using the connector box cable. I was hoping to get closer to the RT97S power >5W but with the H3 HTs it seems like 3W is going to be the top end.

I agree with @dosw keeping it under $100 is going to be a challenge. I did a test recently using a j-pole antenna that i purchased online for ~$39 using both RG8X (~$40) vs. LMR 400 (~$130). It was very surprising to me the difference in power loss between the two cables. If you could put you budget closer to $150 it gives you a few more options. Alternatively, the mag base options from Midland work pretty well for a budget of just under $100 if you could use a ground plane.

Found a combination that works using the Tidradios. I’m not sure what was done differently other than using the H3 radios and trying a different frequency and the connection box. Even with the duplexer they’re putting out about 3W out of the duplexer to the mag base antenna. As a test I put the Boafeng in the exact same configuration. I could only get them to work on the .600 pair. But they were pushing closer to 5W out.

I'm now leaning more to a connector problem (either the direct wire or the connector box (shown in a prev post)) coupled with a possible duplexer problem. I've swapped btwn 2 cords and the connector box, all combinations of 6 different radios (from 2 different man'f), high side/low side connections on the duplexer, antenna combinations, frequency pairs, etc. I can still get a receive and transmit using either the cords or the connector box (this box only works with H3's) when not connected to the duplexer. Using the connector box, the transmit radio does key up on today's trials but it doesn't stay in transmit long enough to actually say anything. I am still open to new thoughts or ideas and will give it some more thought over the weekend. I don't have an issue hooking things up and doing some basic troubleshooting, but I'm out of my element and don't have the tools to troubleshoot much further.

A lot of these complications are likely related to privacy tones or something similar. I have radios from several different companies and have not had any issues. (Wouxun, Tidradio, Motorola, and yes, too many Baofengs)

I mentioned that their size was similar to a bubble pack radio and I think it may have been misunderstood.

I did try one like it but the one I had did not work. It may be a bad one but I had better results with just the wire with the appropriate jacks on either end.

I haven’t tried it. Won’t be able to test it til Friday but definitely worth the attempt. Thanks for the tip.

@marcspaz Yes, using cable exactly as you describe with Vox. Yes, it seems to work without going to the duplexer using whip antennas. There’s some background noise but I figure that’s due to the proximity of the antennas. This is what happens. As a separate troubleshooting effort, I moved the common antenna away when the HTs were connected at one point. Still nothing. It seems to be on the receiving radios output or the transmitting radios input. But the connection cable works fine without the duplexer so I’m leaning more to duplexer issue. I’m open to suggestions.

Tried it again with another set of radios. Works ok enough without the duplexer (less desense). But, it still doesn’t transmit from the speaker of the receive to the mic of the transmit.

I did a lot of reading on the forum from different posters and watched all the YouTube vids that I could find. And despite most people saying it wasn't worth the effort, I was still hoping that this would be a good project to work on with my kids-get them off the screens and find more interest in something tangible-ish. I know that the choice in budget HT's is not ideal, but this would be used only for family communications at a rural property very intermittently. We don't quite get full coverage so the idea would be to take this suitcase repeater out to a hill, hook up an antenna and use it while we're out and about. However, it didn't take long before I hit a roadblock. I wanted to test out the new 50W duplexer tuned for the 462.725/467.725 pair with a couple of HTs that I originally planned to use in the build. The first issue I had was the mic jack on one of the radios is damaged and wouldn't transmit to the receiving radio on the mic to speaker cord. So that radio will be moved to the handheld function and not connected to the duplexer. The input / output tones and frequencies were all checked, and everything worked well without using the duplexer (see pic "Function w-o Duplexer"). Yes, there was a significant amount of desense as expected. I turned the power to low on the receiving radio. I tried the vox at 1 and a 9 without noticing much difference. I did have to put the volume down very low on the receiving radio to minimize feedback. Next, I hooked both radios to the duplexer and immediately, the transmit radio (on right) began transmitting as shown with the red light (pic "Connection Transmit"). Initially, I thought it was caused by something in the duplexer recognizing that there was something to transmit. The indicator light was on for several seconds, then flashes a couple of times and then the radio goes into normal standby. With same two radios used on the non-duplexer test, one set to 467.725 and the other to 462.725, I tried to transmit. I get the green receiving light on the left side receive radio (467.725) but nothing coming out of the transmit radio on the right side (see pic "No go w Duplexer"). The radios are the GMR-5RH which seem to be a re-badged UV-5G. The menu is almost identical to the AR-5RM (that's the one with the broken mic jack). I've gone through the menu's multiple times on the transmit radio and while there are a couple of different settings that seem to relate to the repeater function, they seem to be related to squelch tail. I did try changing some of the settings but I'm hoping someone can point me in the right direction. Is the issue radio setting related - receive or transmit? Duplexer related? Radio function in general related? Thanks in advance.

Not the best if you want to use for repeater work, but good enough if you know the frequencies/repeaters beforehand.

Yup. I did use the software to put in tones though. The total number of channels is limited (only 37 total channels including 1-22, FRS & GMRS)

These MP31 radios are GMRS radios and programable using the Baoefeng software. However, their size is very compariable to the bubble pack radios.

Google is sending me to the same link as i found earlier ... Repeater Duplexer 50W UHF 6 Cavity Duplexer SGQ-450D -

It's been about a year since we got these and they are by far the most used radios in our household. We use them for simplex in the neighborhood when we're out walking or biking. They have had multiple slips, trips, and falls from bikes and scooters. We get coverage from inside the house to a point about 0.5 mi away in an urban neighborhood with lots of mature live oak trees. If both radios are outside, it's closer to 3/4 mi. I can hit a local repeater from inside Walmart at about the same distance without any problems. Actually, reaching the repeater can be done from inside my house at almost 2 mi away (elevation matters). For a <2W radio that's as small as the bubble pack radios and costs ~$13 ea, we've been very pleased. They're going back to the beach this year where it all started. There's more repeater coverage now so I'll have to reprogram them. I guess that's the biggest complaint is that there are not many DIY programmable channels. Otherwise, we've been happy with the purchase.

From BuyTwoWayRadio?

@LeoG Where did you order the SGQ-450D from and did they do the tuning before sending it?

I guess I can justify my LMr400 cable as a Fathers Day gift (even if I ordered it last week).

Since it’s been a year and I’m still dabbling in GMRS I decided to splurge on 50’ of LMR400 to connect to the J-pole on a stick that I showed previously. It arrived today and I thought it was time to do a test. This is just a relative comparison test. Checking the output of the radio I was getting about 9W as a baseline. I connected the radio to the Surecomm with just a rubber ducky antenna on the antenna side recognizing that this is not a good combination but it was consistent for the testing. Using the RG8X I measured 1.37W at the end of the cable. Next, I did the exact same test with the LMR400 and got 6.07W. I was surprised at the results so I did it again and saw the same. I realize that the LMR400 is a better cable but I did not expect to see such a large difference.

The availability of those repeaters covering multiple frequency pairs is what brought this question up. I was curious why the packaged repeaters were able to cover multiple pairs when the one on BuyTwoWay had to be tuned for a specific frequency pair. It seems like it’s somewhat of a compromise but you get the convenience of a pre-packaged unit. Something to think about.

Thank you for that info. That was already taken into account in my plan.

That’s my plan. I was just curious about why that was necessary and if other non-turned for frequencies might work. It appears like they might but at a costs in performance. Once I get it set up I’ll do some test to see what the difference is.

@SteveShannon Thanks a bunch for the link. I did try to search just like that poster and read several of the results but did not see the one you sent. I have some reading to do.

I've been looking into building a briefcase repeater using a couple of HT's. It's a summer project I'm working on with my sons. It'll be used mainly for personal communication at some rural property where we don't quite get good coverage with HT's. I will probably order a tuned duplexer from BuyTwoWayRadios. The 462.725/467.725 pair is fairly open in the areas where I might be traveling and there are no repeaters near the property. I can't find a good explanation as to why the duplexers need to be tuned for a specific frequency pair. Why wouldn't a duplexer tuned for GMRS UHF bands be able to cover all pairs as long as the TX and RX radios had the proper offsets on them? As usual, thanks for your help and Happy Father's Day...